Method for assembly of a rotary piston internal combustion engine

ABSTRACT

A method for assembling a rotary piston internal combustion engine, especially of trochoidal construction, in which the intermediate part with inserted bearing is slipped axially with respect to the eccentric shaft over an eccentric until it abuts at the side of the bearing pin facing the intermediate part; the intermediate part is then pivoted in such a manner that with the area of its circumference not abutting at the bearing pin it comes to lie over the latter while the intermediate part is simultaneously pivoted back, the intermediate part is then displaced radially while being pivoted back, and finally the intermediate part is slipped over the bearing pin with simultaneous complete pivoting back of the intermediate part into its original position.

United States. Patent 11 1 11] 3,868,753 Springer et al. Mar. 4, 1975 METHOD FOR ASSEMBLY OF A ROTARY 3.694.113 9/1972 Jones et al. 418/60 PISTON INTERNAL COMBUSTION ENGINE FOREIGN PATENTS 0R APPLICATIONS Inventors: Willi Springer, ndau; Walter 26,447 0/1968 Japan 4l8/61 Bellmann, Esslingen, both of Germany Primary E.\umi1zerC. W. Lanham [73] Assignee: Daimler-Benz Aktiengesellschaft, Asslswm 'f C Stuttgart, Germany Attorney, Agent, or FirmCra1g & Antonelli [22] Filed: Jan. 30, 1973 [57] ABSTRACT [21] Appl' 327950 A method for assembling a rotary piston internal com- 1 bustion engine, especially of trochoidal construction, [30 Foreign A fi ti priority Data in which the intermediate part with inserted bearing is Jan H Germany M0424] slipped axially with respect to the: eccentric shaft over an eccentric until it abuts at the side of the bearing pin [57] U S CL 29/156 4 R 79/434 108/167 facing the intermediate part; the intermediate part is 15/00 then pivoted in such a manner that with the area of its [58] Field 418/60 circumference not abutting at the bearing pin it comes to lie over the latter while the intermediate part is simultaneously pivoted back, the intermediate part is [56] References Cited thenv displaced radially while being pivoted back, and finally the intermediate part is slipped over the bear- UNITED STATES PATENTS ing pin with simultaneous complete pivoting back of gf 33523 6; the intermediate part into its original position. t. immermann t r 3.575.557 4/1971 Yamamoto .1 418/61 A 5 Clai 3 Dra ing Figures 1 METHOD FOR ASSEMBLY OF A ROTARY PISTON INTERNAL COMBUSTION ENGINE The present invention relates to a method for the assembly of a rotary piston internal combustion engine, especially of trochoidal type of construction, with a housing consisting essentially of two casing parts two end parts and an intermediate part and with two pistons which rotate on two eccentrics of an univided eccentric shaft which includes a bearing pin intermediate the two eccentrics which is adapted to be supported in a bearing of the undivided intermediate part, whereby the inner diameter of the bearing is larger than the diamter of an eccentric and the width of the intermediate part is larger than the intermediate space between the bearing pin and each of the two eccentrics.

Such a rotary piston internal combustion engine with two disks and an eccentric shaft supported three times has already been proposed heretobefore. With this engine the assembly of eccentric shaft and intermediate part takes place in such a manner that the intermediate part is slipped axially to the eccentric shaft over an eccentric,- then is displaced radially for overcoming the radial offset between the eccentric and the bearing pin and finally is slipped axially over the bearing pin. Since the width of the intermediate part for constructively desired reasons is larger than the axial intermediate space between the eccentric and the bearing pin, the mentioned radial displacement of the intermediate part has been made possible with the engine proposed heretofore in that the width of the bearing is considerably smaller than the width of the intermediate part and that the intermediate part includes laterally such recesses or cutouts that the width of the intermediate part in its radially inner area is equal to the width of the bearing and therewith is smaller than the axial intermediate between the bearing pin and the eccentric. These recesses, in order to fulfill their purpose, have to extend radially outwardly so far that only very little space is left over in the radial direction in order to arrange seals between the intermediate part and the pistons. This space, at most, suffices for a gas-sealing ring, however, no oil sealing rings can be provided. This limitation is not acceptable at least with oil lubricated rotary piston internal combustion engines.

.The present invention is concerned with the task to provide a method for the assembly of a rotary piston internal combustion engine of the aforementioned type which permits to leave unchanged the width of the intermediate part to such an extent that the contact surfaces between the piston and the intermediate part are sufficiently large for the accommodation of necessary parts, especially of gas and oil seal rings.

The underlying problems are solved according to the present invention in that the intermediate part, with inserted bearing, is slipped axially to the eccentric shaft over an eccentric until it abuts at the facing side of the bearing pin overa part of the circumference thereof, that thereupon the intermediate part is pivoted in such a manner that it comes to lie with the area of the circumference not abutting at the bearing pin, above the bearing'pin and within this area no longer lies over the eccentric, that subsequently the intermediate part is displaced radially under simultaneous partial backpivoting until the locations of the center longitudinal axes of the bearing and of the bearing pin differ only slightly'from one another, and that finally the intermediate part is pushed or slipped over the bearing pin under simultaneous complete back-pivoting. v

As a result of the method according to the present invention, the assembly is possible with an intermediate part whose width is constant up to the bearing so that the contact surfaces between the intermediate part and the pistons has a sufficient dimension. The diameter of the bearing has to be made only slightly larger than the diameter of the eccentric so that the circumferential velocity of the bearing pin can be kept slight in a favorable manner.

In an advantageous embodiment of the present invention with a method for the assembly of a rotary piston internal combustion engine having a housing whose intermediatepart is wider than the associated bearing, this hearing with its entire width is located always laterally of the eccentric after the abutment of theintermediate part at the side of the bearing pin. As a result thereof, it is possible to make the difference in the diameters of the bearing and of the eccentric so slight as isjust barely necessary for the purely axial slipping over of the bearing over the eccentric. Also oil discharge bores may be provided thereby in the intermediate part directly adjacent the bearing so that the main proportion of the oil lubricating the bearing does not reach the interior space of the engine.

v The method according to the present invention has been described so far in such a manner that the eccentric shaft is held fast and the intermediate part is moved relative thereto. It is, of course, understood that only the relative movements between these parts is of importance-in connection with the method of this invention. Consequently, it is within the purview of the present invention and also within the desired scope of protection to cover realizations of the method of the present invention in which the intermediate part is held fast and the eccentric shaft is moved relative thereto or both partsare moved simultaneouslyto achieve the relative movements indicated above.

Accordingly. it is an object of the present invention to provide a method for the assembly of a rotary piston internal combustion engine which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a method for assembly a rotary piston internal combustion engine, especially of trochiodal construction which assures sufficient space for the installation of seals between the intermediate part and the respective piston.

A further object of the present invention resides in a method for assembling a rotary piston internal combustion engine of trochoidal construction which permits a 4 lubrication of the engine with the use of oil as lubricant pin.

These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in-connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. 1 is an axial longitudinal cross-section view through an assembled rotary piston internal combustion engine in accordance with the present invention; and

FIGS. 2 to 6 are partial somewhat schematic views indicating the individual steps involved in the assembly of the rotary piston internal combustion engine in accordance with the method of this invention.

Referring now to the drawing wherein like reference numerals are used throughout the various views to designate like parts, and more particularly to FIG. 1, the housing of the rotary piston internal combustion engine essentially consists of two casing parts 1 and 2, of two end parts 3 and 4 and of an intermediate part 5. An eccentric shaft 6 is supported in the housing, and more particularly, in the two end parts 3 and 4 with the aid of slide bearings 7 and 8 and in the intermediate part with the aid of a slide bearing 9 which is disposed on a bearing pin 10 of the eccentric shaft 6. Two pistons and 16 are supported on two eccentrics 11 and 12 of the eccentric shaft 6 with the aid of two slide bearings 13 and 14, respectively. Reference numeral 17 designates conventional sealing bars in the piston corners, reference numeral 18 sealing strips of the piston 15 and 16 and reference numeral 23 oil sealing rings.

The bearing pin 10 and the slide bearing 9 are narrower than the intermediate part 5 so that adjacent the slide bearing 9 oil collecting grooves 19 as well as oil discharge bores 20 can be provided in the intermediate part5 which carry off the lubricating oil fed to the slide bearing 9 in a conventional manner not shown.

The bearing pin 10 has a slightly larger diameter than each of the two eccentrics 11 and 12 so that the intermediate part 5 together with the slide bearing 9 can be slipped over the same. However, since the axial intermediate space between the bearing pin 10 and each eccentric 11, 12 is less than the width of the intermediate part 5, the latter can be slipped over the bearing 10 only with the aid of the method of the present invention which will be described more fully hereinafter by refer ence to FIGS. 2 to 6, if one does not wish to subdivide the housing of the eccentric shaft 6.

According to FIG. 2, the intermediate part5 together with the slide bearing 9 is at first slipped axially over the eccentric 11 until it abuts laterally at the bearing 10, i.e., at a portion of the lateral circumferential surface of the bearing 9. A radial displacement of the intermediate part is now not possible because the slide bearing 9 would then be seated immediately on the eccentric 11. The second step of the method according to the present invention (FIG. 3) resides in that the intermediate part5 is pivoted in such a manner that it comes to lie over the bearing 10 with the area 5a of the cir- FIG. 5, the pivot movement of the intermediate part 5 is not obstructed by the casing part 2 so that the casing part 2 can be assembled with the eccentric shaft 6 already prior to the assembly of the intermediate part 5. If the intermediate part 5 has been finally radially displaced so far (FIG. 6) that the positions of the center longitudinal axes 21 and 22 of the slide bearng 9 and of the bearing pin 10 differ only very slightly from one another, then the intermediate part 5 can be slipped over the bearing pin under simultaneous complete pivoting back so that it assumes the position of FIG. 1.

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and we therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

What we claim is:

l. A method for the assembly ofa rotary piston internal combustion engine which comprises a housing composed of two casing parts, of two end parts and of an undivided intermediate part, and two pistons which rotate on two eccentrics of an undivided eccentric shaft which includes a bearing pin intermediate the two eetric and the width of the intermediate parts being larger than the intermediate spacing between the bearing pin and each of the two eccentrics, comprising the steps of causing relative movement between the intermediate part and the eccentric shaft such that the intermediate part with inserted bearing is in effect moved axially to the eccentric shaft over an eccentric thereof until it abuts at the side of the bearing pin facing the intermediate part over a part of the circumference thereof with an area of the circumference thereof not abutting the bearing pin lyihg within an area over the eccentric,-

thereupon causing relative pivotal movement between the intermediate part and the eccentric shaft in such a manner that the intermediate part, with the area of its circumference not abutting at the bearing pin, comes to lie over the bearing pin and no longer lies within the area over the eccentric, thereupon causing radial displacement between the intermediate part and the eccentric shaft in such a manner that the intermediate part is displaced in effect radially with a simultaneous back pivoting until the positions of the center longitudinal axes of the bearing and of the bearing pin differ only slightly from one another, and thereafter completing the installation bycausing relative movement between the intermediate part and the eccentric shaft in such a manner that the intermediate part is displaced in effect over the bearing pin under simultaneous complete pivoting back into its original position.

2. A method according to claim 1, characterized in that the rotary piston internal combustion engine is of trochoidal construction.

3. A method according to claim 1, characterized in that the intermediate part is displaced with inserted bearing axially to the eccentric shaft until it abuts at the side of the bearing pin over a part of its circumference, that the intermediate part is thereupon pivoted in such a manner that with the circumferential area thereof not abutting at the side of the bearing pin it comes to lie over the bearing pin, that subsequently thereto the intermediate part is radially displaced relative to the eccentric shaft with simultaneous pivoting movement of the intermediate part in the opposite direction until the positions of the center longitudinal axis of the bearing and of the bearing pin differ only slightly, and that finally the intermediate part is slipped over the bearing pin while the intermediate part is simultaneously pivoted back in said opposite direction until it assumes its installed position.

4. A method according to claim 1, for the assembly of a rotary piston internal combustion engine with a housing whose intermediate part is wider than the associated bearing, comprising the step of so assembling the intermediate part and eccentric shaft that after the abutment of the intermediate part at the side of the bearing pin, the bearing in its entire width is always disposed laterally of the eccentric.

5. A method according to claim 4, characterized that the intermediate part is displaced with inserted bearing axially to the eccentric shaft until it abuts at the side of the bearing pin over a part of its circumference, that the intermediate part is thereupon pivoted in such a manner that with the circumferential area thereof not installed position. 

1. A method for the assembly of a rotary piston internal combustion engine which comprises a housing composed of two casing parts, of two end parts and of an undivided intermediate part, and two pistons which rotate on two eccentrics of an undivided eccentric shaft which includes a bearing pin intermediate the two eccentrics that is adapted to be supported in a bearing of the undivided intermediate part, the inner diameter of the bearing being larger than the diameter of an eccentric and the width of the intermediate parts being larger than the intermediate spacing between the bearing pin and each of the two eccentrics, comprising the steps of causing relative movement between the intermediate part and the eccentric shaft such that the intermediate part with inserted bearing is in effect moved axially to the eccentric shaft over an eccentric thereof until it abuts at the side of the bearing pin facing the intermediate part over a part of the circumference thereof with an area of the circumference thereof not abutting the bearing pin lyihg within an area over the eccentric, thereupon causing relative pivotal movement between the intermediate part and the eccentric shaft in such a manner that the intermediate part, with the area of its circumference not abutting at the bearing pin, comes to lie over the bearing pin and no longer lies within the area over the eccentric, thereupon causing radial displacement between the intermediate part and the eccentric shaft in such a manner that the intermediate part is displaced in effect radially with a simultaneous back pivoting until the positions of the center longitudinal axes of the bearing and of the bearing pin differ only slightly from one another, and thereafter completing the installation by causing relative movement between the intermediate part and the eccentric shaft in such a manner that the intermediate part is displaced in effect over the bearing pin under simultaneous complete pivoting back into its original position.
 2. A method according to claim 1, characterized in that the rotary piston internal combustion engine is of trochoidal construction.
 3. A method according to claim 1, characterized in that the intermediate part is displaced with inserted bearing axially to the eccentric shaft until it abuts at the side of the bearing pin over a part of its circumference, that the intermediate part is thereupon pivoted in such a manner that with the circumferential area thereof not abutting at the side of the bearing pin it comes to lie over the bearing pin, that subsequently thereto the intermediate part is radially displaced relative to the eccentric shaft with simultaneous pivoting movement of the intermediate part in the opposite direction until the positions of the center longitudinal axis of the bearing and of the bearing pin differ only slightly, and that finally the intermediate part is slipped over the bearing pin while the intermediate part is simultaneously pivoted back in said opposite direction until it assumes its installed position.
 4. A method according to claim 1, for the assembly of a rotary piston internal combustion engine with a housing whose intermediate part is wider than the associated bearing, comprising the step of so assembling the intermediate part and eccentric shaft that after the abutment of the intermediate part at the side of the bearing pin, the bearing in its entire width is always disposed laterally of the eccentric.
 5. A method according to claim 4, characterized that the intermediate part is displaced with inserted bearing axially to the eccentric shaft until it abuts at the side of the bearing pin over a part of its circumference, that the intermediate part is thereupon pivoted in such a manner that with the circumferential area thereof not abutting at the side of the bearing pin it comes to lie over the bearing pin, that subsequently thereto the intermediate part is radially displaced relative to the eccentric shaft with simultaneous pivoting movement of the intermediate part in the opposite direction until the positions of the center longitudinal axis of the bearing and of the bearing pin differ only slightly, and that finally the intermediate part is slipped over the bearing pin while the intermediate part is simultaneously pivoted back in said opposite direction until it assumes its installed position. 